The present invention relates to an improvement in separators for separating lighter liquids from heavier liquids, particularly from separating oil and grease from water, such as is found in commercial kitchens.
Commercial kitchen warewashing sinks generate large volumes of water, along with a substantial quantity of fats, oils and grease within the water. The fats, oils and grease are the by-products of cooking and washing operations. Together collectively they are referred to here sometimes as oil/grease and sometimes as FOG, the acronym for “fat, oil and grease.”
Various products have been used to make these sorts of separations over the years. The separation is important because the oil/grease can congeal in downstream pipes, causing clogging, particularly as built up over time. Sewer districts have in many jurisdictions imposed requirements that FOG be removed from commercial kitchen effluent before it is discharged to the sewer. This invention is particularly useful in connection with those types of installations, but also will find the utility elsewhere.
Most separators take advantage of the fact that the oil/grease is immiscible with the water and has a lower specific gravity. Thus, over time the oil/grease will float to the surface of the water. Among the products that have been used in the past to remove FOG from effluent are two products that are sold by Thermaco, Inc. of Asheboro, N.C.
In Thermaco, Inc.'s Big Dipper® product, a partially submerged oleophilic wheel rotates partially submerged in the oil/grease surface, and pulls the oil/grease upwardly out of the liquid, where it can be scraped off and diverted to a container.
Another Thermaco product is one that is described in U.S. Pat. No. 6,849,177 for a grease separator for kitchen sinks and other applications. In that grease separator design, one end of an outer housing has a fitting into which effluent from a kitchen sink is introduced. The outer housing has an inner housing that receives an effluent from a kitchen sink, and a drainage port from the inner housing extends from the outer housing to go to a drain. Intermittent large flows, such as are typical when draining a large kitchen sink, can raise the static water level within the inner housing above the drainage outlet. This causes oil/grease that has accumulated near an upper portion of the inner housing to flow over into the outer housing. Drains in upper parts of the outer housing can be used to drain the oil/grease from the outer housing. In this apparatus, there is a clearly defined inlet end and outlet end to the separator. Thus installation of the separator requires kitchen sink piping and sewer piping to be correctly positioned in the respect to the separators ports. Also, the apparatus as disclosed in that patent takes up a considerable amount of floor space, which can be at a premium, particularly in a commercial kitchen such as for a fast food restaurant.
Accordingly, there is a need in the art for an improved separator that is easier and more foolproof to connect and has the potential for taking up less floor space.